well, after driving in the snowy conditions today, i was sitting at a stoplight in the vr4 and noticed that my idle seems to drop a little and then catch. my car seems to shake or stutter, it's nothing major but it's not running at a constant condition? i really don't know what i'm saying but what's with the weird idle? possible situations? thanks. also, could someone describe what engine knock is like? thanks again. you guys rule